Field
The present disclosure relates to lighting, devices and methods. In particular, the present disclosure relates to method and system for pixel combinations of color and white lighting devices for a video display screen.
Related Art
Video displays can use light emitting diodes (“LEDs”) because of the brightness and low power requirements of the LEDs. LED video screens can be used in, for example, digital billboards to display, for example, advertisements, textual and/or graphical informational messages, and live or prerecorded videos. LED video screens, also referred to as LED display walls, are made up of one or more individual panels and/or intelligent modules (“IM”) having a predetermined number and arrangement of controllable LEDs. The panels and/or modules are mounted net to each other and their outputs are controlled such that they appear to be one large display screen.
The LEDs used in the LED video screen, etc. are usually red, green end/or blue (“RGB”) LEDs whose output can be controlled such that the RGB components mix according to known principles to create any visible color (including black and white).
However, when an RGB LED is configured to emit white, light, each of the red, green, and blue LEDs of the RGB LED are require to emit their respective colors to produce white light, which increases the driving current of the RGB LED. Further, RGB LEDs used for modules, panels, etc. may have different wavelengths of color due to, for example, their composition, manufacturing variations, and/or other differences. As a result, LEDs on the individual panels and modules may have different output coloring from panel to panel and module to module. These variations can cause RGB LEDs configured to emit white light to also emit one or more tertiary and/or secondary colors. Further, the individual colors of the RGB LEDs can be distinguished from each other at close distances. Since panels comprise multiple RGB LEDs and video screens comprise multiple panels and/or modules placed next to each other, uniformity of the screen's output will be affected by the color differences between the LED batches. Further, the cost of RGB LEDs is greater than the cost of white LEDs. Therefore, panels including RGB LEDs that are configured to emit white light are more expensive than panels included white LEDs.
Accordingly, there exists a need to provide an improved LED panel that can produce white light with increased uniformity and brightness at a reduced cost and having reduced power consumption.